Differential-pressure mechanism.



` s. H. BOWEN, 1. DIFFERENTIAL PRESSURE MECHANISM. l y

APPLICATION FILED SEPT. I4. I9l5.- I I I j Patented Aug. 14, 1917.

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4 vgmoz I H. BOWEN. Jn, mrffnewmL PRESSURE MECHANISM.

MPLlCATlH FILED SEPT. I4, 1915. l

Patented Aug.V 14, 1917.

GEORGE H. BOWEN, JR., 0F TORONTG, ONTARIO, CANADA.

DIFFERENTIALPRESSURE MECHANISM.

Specification of Iietters Patent.

Patented Aug; 14;, 1917.

Appnanun :una september i4, 1915. seria1N05o,5s1.

To all 'whom t may concern:

Be it known that 1, Gnoaor. H. BOWEN, Jr., a citizen of the Dominion of Ganada, and a subject of the King of England, residing at No. 20 Tennis Crescent, in the city of Toronto, county of Yorin Province of Ontario, Dominion of Canada, have inve11ted certain new and useful lmprovements in Difl'erenti:tl-Pressure Mechanism, of which the following is a specification.

The object of the invention is to provide a cheap, simple and eiiicient mechanism for use in the class of machines that are operated by liquid or other iuids or through which liquid or other fluids pass.

The invention is directed to a mechanism in which there is comprised astationary member and a rotor 4'haring projecting vancs, the areas of" which are automatie cally varied to present different areas to a Huid engaging them as the rotor revolves. Such a mechanism can be yutilized as a subf stitutc for many 'mechanisms which depend upon the Well known 'cylinderand piston or in place'of mechanisms that depend uhon the common rotor and stator of the present day turbine. Y

The invention is applicable to such machines, for example, as steam engines, steam turbines, steam meters, steam pumps, Water engines and motors, water turbines, water or other liquid meters, pumps, gas or air engines, gas and air meters, gas or air pumps, and gas'or airi compress(irs.V

. As showing certain specific embodiments of the invention reference is madeA to the drawings forming a pnrtpof the specification and in which drawings,

Figure 1 shows a horizontal sectional View of a mechanism embodying my in\en tion. This is a view taken on the' line l-1 of Fig. 2. l

Fig. 2 is a vertical sectional View of the same mechanism taken on the line 2--2 of Fig. 1.

Fig. 8 is a` vertical sectional view taken as on the broken line Bw?, of Fig. 1.

Fig. 4 is adetail View of a part of one of the venes.

Fig. 5 is a horizontal sectional view of `another form of mechanism embodying my invention.

This a yView taken as on the line 5-5 of Fig. 6.

Fig. 6 is a vertical sectionalview of the mechanism shown in Fig. 5, and is a view taken as on the line 6--6 of Fig. 5.

Fig'. 7 shows a developed cross section of the cylinder' and rotor taken as on the circular line E, F, G, H, E of Fig. 5. l

Fig. 8 is a vertical cross sectional vview of another machine which embodies my invention..

Like reference characters refer to like parts both in the drawings and in the specification.

The machine shown in Figs. 1 to 3 comprises an outer member or casing 1 which is preferably a stationary member, and an inner member which is preferably the rotatable member or what is frequently referred to as the rotor. The casing comprises the circular member or hollow ring 3, lower head 4 and upper head 5. The heads are bolted to the 'ring 3 inthe manner which is common in engine construction. A shaft G extends through the heads and the joint between the shaft and the head 5 is 'revented from leaking by the usual packmg and gland construction, 7 and 8. There is located within the lower portion of the casing a cam member 9, the function of which will hereinafter' be described more in detail. This cam member 9 is provided with a depending flange that surrounds the shaft 6 and the leakage between the shaft 6 and the cam member 9 is prevented by the usual packing and gland construction 10 and 11, while ythe leakage from between the head 4 and cam member` 9 is prevented by the packing 12 and gland 13.

The'shaft 6 carries a hub 14 and from this hub there projects a number ofy vanos.

Each of these 'vanes comprises a main portion 15 which is slotted at 16, and in this slotted portion there is located, so as to be free to slide therein, a member 17 which may be referred to as the movable portion of the vane. The movable portion 17 is continuously pressed downwardly against the upper surface of the cam member 9 by springs 18, and in order that the part 17 will remain in propel' alinementa slot and key or feather construction is provided. The slot just referred to is indicated by the numeral 19 and a fehther is indica-ted by the numeral 20X This movable member may be ing i5 inforced as by braces l5 which 50 rain ine-mbe provided at the lower portion thereof, for example at ythe lower end of the feather, with antifri'ction rollers, as 18 (see Fig. ll), These rollers can be utilized as projectbearingsurfaces to take the wear of of the movable portions or varies 1T as they travel along the cam since a line contact of the movable portions with the cam is uii desirable.

The inain portions of the varies are shown integral with the hub 14 lbut it will be manifest that they may be separateiinern bers which are secured to thehub in any suitable manner. The vanes inay also be reare secured in place by bolts l5 that pass through the main portion l5 und also through slots lt in the movableportions 17.

In order that the fiuid passing through 2o the casing may assist in inoving or in liolding the portions 17 against the upper surface of the cani, passage-ways may be provided in the inain portions at X. These piissageii'ays lead to the space Y above the movable portions .t7 and are provided with check valves Z that permit a tlow ot' fluid only from the exterior of the vanes to the space* YA A The tops and ends of the inain portion 15 are provided respectively with pac-kings 2l andj'zl. and the bottoms and ends of the Inovable portions are provided with packings '21 and, Q1 which are Similar in their action to the packingtrings found in pistons of eii gines. ln other words.' the packings '21, 2l

Q ."1 and 2l serve to prevent the escape or flow of fluid' through the Spaces between the inenibers of the movable member and the members constituting the casing. These 40 packings also serve to counteract tor wear und incquaiiticsof the surfaces engaged by them `and they serve tight.

The cam member 9 is constructed so that all of the substantially radial elements of its' upper s'iirfaceextend horizontally and conscouently 'as the rotor revolves the lower edge or lower part of the movable portion 17 can engage or at least almost engage the and make a coiiipai'utively tight fitwith the latter. As thc rotor revolves the movableportion 17 of the vane which is shown at the'lett hand side of Fig. 2 will gradually vbe forced to the position olc thc movable pcrtionfolt the vane shown at tho side ot the figure, and it 'will right hand position the -lic observed that in thc latter lower edge ofthe portion 17 will rest on the surf' e along thc line in, instead of along a surface which has the elevation ol' thil line wi. ln other 'words the projecting vani has decreased in area as it has moved a certain 'aiigle-i-in the machine shown this' :ingle is i I ,l

approximately lbf) --but will assainir its iii- 6.5 creased arca wht-ii it has completed an cnto maintain the machine tire revolution. The cam member 9 is provided with a circuniferential packing 21.

The casing is provided with any suitable support or standard as S and `with ports or openings and 24 which communicate with Spaces and .6 having terminal orifices 25 and 26. One ot' these portsor openings and its corresponding space inay be considered as a supply port or opening, while the other port or opening and its corresponding space may be considered as as exhaust port; or opening, since when an incomingr tiuid is beingl supplied to the mechanism through one of the openings an outgoing fluid will be passing from the iiiechanisin to the other port or opening. When a li uid is being forced into the machine through the ope1iing 23 it will cause the rotoi-,to revolve because of the diticei'itial exposed arcas ol the varies. The cani-shaped member t) is pr vided with a handle 27 and by merely rotat y ing the cani 9 through the medium ot said handle the engine cran be driven either forward or backward because this cam changes the relative position ot' the vane arcas in rcspec-t to the inlet opening of the machine, or its speed-can he ,otherwise moditied by the cain as"dcsircd. Any suitable means, as the screw 27', can be utilized'to secure the han,- d'le and hence the `cani in adjusted position.

This cam can be used also to calibrate the diti'erential inechanism should'it he desired to do so, lll/'bile the cain!) is shown as being movable and adjustable Istill it will. be manifest that it may be considered as a part of vthe lower head 4 and in fact could be inale an integral part thereof in case the,

"the casing could lic regulated'l by any suitable governor, as t'or instancil one which might he' placed upon the supply pipe leading toithc casing. The length of the huh or collar Mis slightly greater than the dis-4 tance 4between the under side of the head 5 and the lowest hart ol the upper surface olI the cam t) and this huh enters the rounter-bored portions and 5) in the upper licad and calin incinbci' respectively. This ini serves to insure the rotor boing properly liositioncd relative to thc members which uro onliter-hound sons to receive the hulrl/t ol' the rotor. 'llhc'shal't' (l may also he pi'ovided willi collars 25s and 29 on thiinner sides'of which may hc located halls that receive thrust and serve to overcome the friction. These collars limit the longitudinal movement of the shaft and also tend to reinforce the heads 4 and 5. Theshaft 6 in the construction shown in centrally located within the casing but in a broad 'sense the invention would be realized in a construction in which the movable portions ofthe vanes move radially outwardly, that is away from the shaft (3 instead of up and down, that is parallel with the shaft (3 as in the construction' shown. lVhile the movable portions 17 have been shown as straight still they might be constructed so as to beV curved should occasion require. l

The machine shown in "Figs, 5, 6 and 7 is similar in Vits construction to that shown ,and described'in connection -vvith Figs. 1,

. 2 and 3 and this being the case it is believed that a detailed description of all of the parts of the machine shown in Figs. 5, 6 and 7 is unnecessary; certain features, howei er, will be referred to. YIhe main portions of the vanes of the rotatable member of the .mechanism are provided with. a counterbored opening 51 and a comparatively long bore The movable portions of the vanes are provided with laterally extending ears 53 from which there extends upwardly rods 54 that slide in the bored opening Compression springs surround these rods and the lower end 5of each of these springs is seated upon -th'e upper side of a laterallyextending ear 53; the uppbr portion of each of these springs is seated in the counterbored opening 51 and this spring mechanism just described constitutes ameans for forciblyl pressing the lower part of the movable portionof each vane toward the cam surface with which it coperates. Each of the laterally extending ears 53 is inclined upward away from the movable portion from which it projects thus forming a means whereby the movable' portion of the vane can slide along the'inclned portions of the cam without causing udue friction. The cam with which these movable portions of the vanes eoperate is designated by the numeral 56 and a developed section of this cam is clearly shown in Fig. 7. The cam 56 is shown as being movable relative to the lower head. of the casing.4

In Fig. 8 there is shown a'machine which is similar to the machine shown in Figs. 1 to 7 inclusive. In Fig.` 8, however,= the cam at the lower part of the machine is Shown as being integral with the lower head yfof the casing and consequently this cam is "not adjustable relative to said head. This cam and head which are integral are designated by the reference character 57 and 1t will be noted that the shaft 58 of the machine shown in Fig. .8 does not extend through the head 57 but merely projects into a bored portion of the latter. When this construction is used a cam may vbe provided -the main portion of the vanes that are on the rotor. If desired movable cam similar to cam 59 could be employed in the form of machine shown in- Figs. 1 to 7 but if..employed with such machines it would be advisable to have the cam member 59 movable with the lower cam member, such as with the lower cam4 member 9 'in the machine shown in Figs. l to 3, or the cam member 56 in the machine shown in Figs. to 7.

The cam member 9 may be considered to havea low surface A, a gradual changing or cam surface B, a high surface G and a gradual changing or cam surface D. The surface A is arbitrarily referred to as the low .surface since it is the surface which is the farthest removed from the main portion of each vane. In other Words, When the movable portion is in. engagement With this low surface the maximum area of the vane is exposed. The surface C is arbitrarily referred to as the high surface sir-ce this is the surface which is the nearest to the main portion of each vane. In other Words, when `the movable portion of a vane is in. engagement with this high surface the minimum area'of the vane is e). posed.

The several surfaces of the cam member 9 are constructed so that at the time the movable portion 17 of a vane engages the low surface said movable portion does not move relatively to the main portion 15 of the vane i l and during the time that any particular vane is traveling over the low surface the maximum area of the variable vane is exposed to the iuid operating upon. the vane or to the fluid which is operated upon by the vane.

.The high and low surfaces may be considered as unchanglng surfaces since all portions of each of said surfaces are uniformly spaced from the main portion of a vane when said portion is moving opposite any one of said surfaces.

'In a machine such as illustrated, in which the movable iportion of each vane moves or` cated the minimum area of the variable vane.

' pushed upwardly against the action of 'fluid passes is exposed to the fluid operating upon the vane or to theiluid being operated upon by the, vane as the case may be. The movable portion of each vane moves relatively to the main portion only when the vane islpassing 'from the high surface to the low surface and from the lowsurface to the high surface. This movement of the movable lportion relative to the main portion takes place when the vane is moving over the capi surface B or cam surface D, as' the ease may be. These cam I:surfaces are in effect helical surfaces. lf. for example, the motor is moving so that each vane succemively engages and passes over the ,low surface A, cam surface B, high surface (l and cam surface D then the movable portion of eaclrvane is being. positively its springs by the cam surface B whereby the minimum area of the vane will be exposed when the vane reaches the surface C. The minimum area will remain exposed as the vane passes over the high surface C, and finally the movable portion will be forced downwardly by the springs against the cam surface D as the vane moves from the high surface G to the low surface D so that when the vane reaches the lowr lsurface A the maximum area Wil'lbe exposed.

From an inspection of the drawings it will be readily observed that the cam or helical surfaces B and `D are opposite the spaces 25 and 26 and particularly opposite the ter* minal orifices 25 and 26 through Which the on its way to orrom the ports Q3 and 24, Tli'eresult is that the fluid exerts the sameV pressure .upon opposite sides of each movable portion as said portion is mov ing relatively to the main portion; that is at the time the movable portion is passing over and'n engagement with the cam surface B or eain surface D, as the case may be. Dur ing this time the particular vane in which the movable poton is being moved is not 4doing any work and there is very little friction between the movable and main portions of the vane'. While the movable portion of the vane is being moved relatively to the main portion the movable portion maymake only,7 a. line contact with the cam surface which it engages. When, however, any particular vane is doing work the area thereof is not changing and the portions of the 'vane which are adjacent or opposed to the eas- `ing-or the cam member in or of the cas'- iug-can make a surfacecontact With the easing and the ,cam member which it en# gages, thus resultingin a construction which will not readily leak steam., A cam member which is within the casing or a cam member which is a part of the casing may be broadly construed as a cam memberon the interior of the easin". The eiunsurfaees Band D are preferably not quite `eoextensive with the length of the terminal orifices 26'-` and 25',

.quired number of inlets is equal to as it is desimible to have all movements of -the movable portion of the vane relative to the main portion'take place while the balanced pressure vis vmaintainedl on opposite sides 'of the vane the movable pqlrtion Off/'0 which is being moved. i

The differential pressuremechanism shown in the several iigures of the drawings may be considered to have N number of radial vanes and in the "construction shown N would equal 4 because there are four vanes. When the pV rt 23 serves as an inlet then the port Q4. wou d serve as an outlet or exhaust i and it willtherefoi'e be seen that the re-1` k -v i Y the reipnred number of outlets or exhausts i's equal to The terminal orifices 25 and 26 are each of a length approximately equal 8 5 n O to lille low surface A extends over an l p 360C angle at least as great aswN, the cam surface B extends over an angle not greaterv than that of the terminal orifice 26', to Wit, not greater than thel high surface C 360 is at least as great as-A, and the cam surface D extends over an 'an glen ot greater than that of the termicnal orifice 25', to wit, not

greater than It is apparent that the apparatus herein The differential pressure mechanism may be compounded if desired in a mannersimilar to that in which steam engines, air .compressors or pumps are compounded today.

l`he di ll'erential pres-sure mechanism above deseril'ied maniilesily is adapted for use as 110 an.engine or when driven in a reverse direc'- tiou as a pump. ll'hen used asa meter for example the shaft would lie connected to a recording instrument. =lt is therefore maire,

fest that the invention may be employed in `various forms and that various changes might 'he resorted to withtait departing from the spirit and scope of the invention.

What I claim is: i s

l. A differential pressure mechanism ot the class describedcomprising a casing having'receiving spaces with terminal orifices, a rotor within said casing which rotor cornprises vanes each having a main portion/and a portion that moves relatively to the. main portion, there. vbeing a. ram member on the interior of the easing which rain member has high and low surfaces and a cam sur- ,i'aee between each high and low surface,

which cam surfaces do net extend beyond gli IY() casing having receiving when an unbalanced said terminal orifices whereby when a movable portion of a vane is being actuated by said cam the fluid passing through the mechanism will. exert an equal pressure on oppo site sides of tlie vane the movable portion of which is being moved.

2. A differential pressure mechanism of the class described comprising in coinbination a casing having therein Huid receiving spaces and terminal orifices through which fluid can flow :from the receiving spaces to 'the interior of the casing or from the intcrior of the casing to the receiving space, a rotor within the interior of said casing which rotor comprises vanos each having a main portion and a movable portion, said differential pressure mechanism als having a cam member on the interior of the casing which cam member' has high and low sui-- faces, said cam surfaces being arranged only opposite the orifices and the cam ment er being constructed so thatas the movable portion of any particular vane is moved over and in engagement with the low surface or the high surface the movable portion will not move relatively to the main portion of the vane and-so that when any particular vane is moving over any par.- ticular cam surface' pressure on opposite sides of. that particular vane will be maintained equal because of the terminal orifices extending to opposite sides of that particular vane while the movable portion thereof is in engagement with the cam surface,

. 3. A reversible pressure mechanism of the 'class described comprising in combination a casing having aV movable cam member and a rotor within the casing, which rotor comprises varies each having a main portion and a portion which moves relatively to the main portion whereby the exposed areaof the vane can be varied, the movable portion of the `vane being in engagement with the surfaces of the cam member, `the spaces that are pro- .vided with terminal orifices which extend along a portion ofthe path of movement of the vanes, the cam member having high and low surfaces and cam surfaces between the high andlow surfaces, which camysur faces are located opposite the terminal oriices whereby when a movable portion of 4the vane is being` moved relatively to its main portion when in engagement with a cam surface a `balanced pressure will exist on opposite sides of that-particularvane, lthe cam being lconstructed and arranged relatively to the terminal orifices so that pressure is existing on opposite sides of any particular vanethe movable portion moved relatively to its main portion.

4. A rotary fluid device of the class described comprising an annular cylinder or casing closed at the top and bottom by tivov of the vane will not be.

heads, a rotor contained within the cylinder having N radial vanes, said cylinder having -l-T inlet terminal orifices and E: exhaust .provided with '-2- plane surfaces `that are perpendicular to the axis of the cylinder, part of which plane surfaces may be con'- sidered as high surfaces and the rest of which surfaces may be considered as 10W surfaces, the area of each of said surfaces being approximately equal to or great as the area of a sector of a circle containing 3G00 N them an equal number of helical. or cam suie faces, the cam surfaces being opposite to the terminal orifices.

5. A rotary fluid device of the class described comprising an annular cylinder or easing closed at the top and bottom by two heads, a rotor contained within the cylinder which plane surfacesl have between having N radial vanes, said cylinder having l; inlet terminal orifices and exhaust terminal orifices all of which orifices subvane of said rotor having e main portion and a portion movable relatively to the main, portion, the casing of said fluid device having on the interior thereof a cani inember which is provided with plane surapproximately equal to or as great as the" area of a sector of a circlel containing which plane surfaces have between them an equal number of helical or cam surfaces, the cam surfaces being opposite to the terminal orifices, the cam member beingr movable angularly and relatively to the other members of the casing whereby the operation of the fluid' pressure mechanism can be reversed.

6. A {luid pressure mechanism of the class described comprising in combination a casing having terminal orifices, a rotor having vanes the area of which can vary, said casing having on the interior thereof a movable cam member which is engaged with the movable portion of the variablevan'es,whfiqh cam mem ber can be positioned relative to the rest of iso . tion movable relatively to the main portion 1o whereby'the exposed area of the vane can be changed, the casi-ng having@ movable cem member which is engaged by the mov# able jportionsof the venes so that as the venes travel over the cam member the Inovable portionsv of the venes can be positioned -reletively to the mein portion, the earn member being movable relatively to the terminal orifices. o

r8J In a, ldifferential pressure mechanism of the `class described en annular cylinder having inlet and exhzinst orifices,` a rotor with N venes, :L cem member associated with the cylinder and 'coperating with the rotor venes, and cylinder' heads secured tothe ovlindex', the cam member being ladjustable relatively tothe inlet and exhaust oriciq of the cylinder, which cam member lies pleiie,

surfaces perpendicular to the exis of the cylinder, part of which surfaces are in one plane end partnof which surfaces are in an other plane, the area, of eachof said surfaces being' approximately equal to tbs1 area, of a,

sector, cfa circle, containing the plane surfaces being interconnected by en equal number of helical or cem surfaces.

This specification sigr'ied and witnessed the 10th dey of September, A. D. 1915.

GEORGE H BOXEN, JR. Signed in the presence olf--N MARGARET E. HAnni's, FRED H. M IRWIN'. 

